Process for the destructive distillation of petroleum oil



June 24, 1930. A. D. DAVID 1,766,983

` rnocass FoR THE DEsTRuc'x-Ivf: DISTILLATION oF PETROLEUM on.

Filed Feb. 14, 1923 Pafesfed June 24, 1930 y UNITED STATI-:sAParri-:NT.o1-*lucia AUDREY' D. DAVID, OF CHICAGO, ILLINOIS, ASSIGNOR TOTHE UNIVERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATIONOF SOUTH DAKOTA Application filed February 14, 1923. Serial No. 619,037.

This invention relates to improvements in a process for distillingpetroleum oil and refers more particularly to the pressure disltillation of oils to produce relatively light' hydrocarbons having thecharacteristics of gasoline.

Among the objects of the invention are to provide a process in which thedeposited free carbon particles separated out durlng the conversion ofthe oil are removed from I the conversion stage by a flotation mediumand the carbon particles eliminated therefrom in a separate oxidizingstage; to provide a process whereby the oil may be treated over aconsiderable period of time due to the fact that the carbon accumula- Ychamber which is connected by a vapor line 4 to a dephlegmator 5. Thedephlegmator,

in turn, is connected by a line 6 to a water condenser 7,'thedischarge'end of which is connected bya pipe 8 to a receiving tank 9.

A liquid drawoli` line l() from the expansion chamber communicates witha combustion chamber 11 which has a discharge line 12 communicating withthe suction side of the pump 13, the latter being connected through adischarge line 14 back to the chamber 3 so that a continual circulationmay be maintained between the two chambers.

The oil to be treated is introduced from any convenient source throughithe ipe 15 which is looped through the top of t e combustion chamber 11to extract heat therefrom and to pre-heat the oil travelin through thecharging line. The pre-beate charging stock is directed through the line15 which is connected to the heating coils2 l by means of a line 16. Theoil after being heated toa conversion temperatureV in the heating coils2 is discharged through transfer line 17 controlled by a valve 18 intothe expansion or vaporizing chamber 3. In the bottom of the expansionchamber is maintained a body of molten lead as shown at 19. The oil bodyis permitted to collect above this molten lead body, the.level beingcontrolled by means of a draw-oil` line 20 controlled by a valve 21 andtricocks 22. The vapors evolved during the conversion of the oil passoff through-the vapor line 4 and are subjected to dephlegmating andcondensing actions Vin the separate stages 5 and 7. The condensed vaporsare collected as liquid distillate in the receiving tank 9 which isequipped with a pressure relief valve 23,. pressure gauge 24, liquidlevel gauge 25, and liquid draw-oli' valve 26. The pressure on thesystem may be controlled by means of the pressure relief valve ordifferential pressure upon the different stages maintained by the valves18, 27, and 28 positioned between the different stages. A reiiuxcondensate separated out in the dephlegmating stagev may be returnedthrough the pipe 29 controlled by a valve 30 and recycled with the stockthrough the heating sta e. y

During t e conversion of the oil in the expansion or vaporizing chamber3 there will be separated out finely divided free carbon particles whichwould normally accumulate in the expansion chamber. Some of this carbonwould remain in suspension in the unvaporized oil and be carried oif inthe residual products withdrawn from the chamber, while a portion of thecarbon would collect in a relatively solid sludgy or coky mass in thebottom of the chamber. To prevent this objectionable carbonaccumulation, the free carbon particles which are rained from the oilbody during its conversion are collected 0n the surface of the flotationmedium or molten lead which is maintained in the bottom of the chamber.This molten lead has a heavier specific gravity than the carbon and forthis reason the free carbon will remain upon its surface. This otationmedium is withdrawn from the chamber 3 through the line 10 and valveinterposed therein and circulated through a combustion chamber 11, intowhich is introduced a gas such as air through a pipe 31. At the sametime through the pipe 32 is withdrawn the. gaseous constituent-s formedby the colnbustion of the carbonaccous particles with the air introducedthrough the line 31. Valves 33 and 34 are interposed in these lines toregulate the introduction and withdrawal of the gases. It is essentialthat the-introduction' of air be accurately vcontrolled to prevent tooactive flow of the liquid. The vaporizing and combustion chambers arepreferably' operated at substantially the same pressure, the

--diferential pressure conditions which may be maintained therein beingonly suflicient to assure the circula-tion of the flotation medium fromone chamber to the other and such differential pressure as may be causedby the circulating pump 13.

The advantage of the apparatus is readily appreciated, as the carbonaccumulation is practically eliminated, permitting theapparatus to beoperated over a considerable period of time without the necessity ofshutting down for cleaning the carbon from the expansion or conversionstage.

I claim as my invention: V

1. A process for cra-cking petroleum oil consisting in heating the oilto a conversion temperature, permitting the oil to vaporize whilemaintaining it in a substantial body above a flotation medium in anenlarged expansion zone, drawing off the carbon separated out duringconversion by withdrawing the flotation medium from the expansion zone.removing the carbon from the flotation mediuml by oxidation andrecycling the medium back to the expansion stage.

withdrawing the flotation medium, having the carbon supported thereonand subjecting it to an oxidizing action in a separate combustion zone,recycling the carbon free medium back to the expansion zone.

4. A process of converting heavier into lower hydrocarbons, consistingin continuously passing the oil through a heating zone wherein it issubjected to a cracking temperature, in discharging the products ofconversion from said heating zone into an enlarged expansion 'chamberwhere substantial vaporization occurs and carbon is precipitated, inmaintaining a. supply of molten 4metal in said expansion chamber on thesurface of which, said precipitated car-- bon is suspended, incontinuously withdrawing molten metal and the suspended carbon from saidexpansion chamber and passing it to a. combustion chamber wherein thecarbon is oxidized, and in continuously recycling the molten metal freefrom carbon from said combustion chamber to said expansion chamber.

5. A process for treating oil in which combustible solids separate fromthe oil, comprising maintaining a body of heated oil in an enlargedchamber, wherein the combustible solids precipitate out of the oil,continuously removing the combustible solids precipitated out of theoilfrom such enlarged chamber, admitting the same to an oxidizing zone,wherein combustion thereof occurs, and imparting the heat given up bycombustion of said combustible solids in said oxidizing zone to oilbeing supplied to the process, to preheat the same.

AUBREY D. DAVID.

2. A process for cracking petroleum oil consisting in hea-ting the oilto a conversion temperature, permitting the conversion to take place inan enlarged expansion chamber containing a molten flotation mediumhaving a specific gravity in excess of the free carbon particles,removing the carbon from the system by continuously withdrawing theflotation medium from the expansion chamber, subjectingit in a separatestage to an oxidizing action and continuouslv recycling the flotationmedium devoid gf .the carbon back to the' expansion cham-

